HI HOmER,
To change the heder text of your Auctiva store, please log into your Auctiva account and go to Store(Tab) -> Store Header, and update your Auctiva store header text.
Also, if you would like to change your store window header text, please go to Store(Tab) -> Edit Store Window, revise the "Top Text" field, and save your changes. Once this text has been updated, it will be reflected in your current listings the next time the store window refreshes, which it does about every 4 hours.
-Mike